Importing masks and adjustment layers from Phototshop into After Effects

Hi there.
I have a video which is a still shot, no panning or tilting.
It is of trees, mountains and clouds. I'd like to have different levels adjustments for for the trees (which are darkers) and the mountains and clouds (which are lighter)
So I would like to make a very precise mask so I can adjust the levels separately for the different elements.
I'm more familiar with the masking tools in photoshop, so I would prefer to do my work there, using a still image from the video which is the same dimensions as the video. I can set up adjustment layers with masks above the original image and get everything just right. Because the video isn't moving, that same mask could serve for the whole duration of the video.
So my question is: can I import these masked adjustment layers into after effects to use them on the final video? (AFX, after all, also has adjustment layers and masks).
And if, alas, that isn't possible, how might I use masks from photoshops to selectively apply effects like levels, within AFX.
Thanks for your help!
Bevis